Fixed Tube Heat Exchanger is the most common and economical heat exchanger, where both ends of the tube bundle are connected by welding or expanding permanently on the tubesheet that is integrated with the shell. This system is very effective for applications with high pressure and minimal risk of leakage, but has limitations in terms of maintenance, the inside of the shell is not easy to clean mechanically and is difficult to reach, so this tool is best suited for clean fluids or does not cause heavy scale on the shell side.